Application of bow-tie surface plasmon antenna to silicon on insulator nanowire photodiode for enhanced light absorption

Abstract

Down scaling of photodetectors is one of the major approaches to enhance their performance in terms of operation speed, dark current and sensitivity to photogenerated carriers. In order to compensate for the drawback of the down scaling, i.e. the reduction of light absorption efficiency and light receiving area, this report introduces the bow-tie surface plasmon nanoantenna for silicon on insulator (SOI) nanowire photodiode and clarifies its spectroscopic response. The bow-tie structure has a light sensitive area in the scale of the wavelength, and resonantly enhances the electric field near the central gap resulting in increased generation of carriers in the silicon nanowire, which is experimentally verified and analyzed by electromagnetic simulation.